# What is an ESP? A service for managing and sending email

An email service provider (ESP) is a platform used to send newsletter campaigns and, depending on the service, manage subscriber records and suppressions.

An ESP can hold subscriber lists, send campaigns and maintain a suppression list of addresses that must not receive future sends. Feature coverage differs between providers.

## Following a newsletter through a provider change

Illustrative migration checklist: the old platform sends from newsletter.publisher.example and stores suppressions; the new platform may use a different sending setup and list state. Before sending, the publisher maps who controls subscriber records, suppression and message headers, then tests a delivered message.

## ESP describes the service, not the audience owner

When changing providers, test an unsubscribed address as well as an active subscriber. Moving the active list and email design without preserving suppression records can cause the new system to send to someone who already opted out. Confirm the actual delivered sender identity too.

## Inventory what would move with you

Before changing providers, identify the lists, suppression records, sending domains, signup forms and automations your publication uses. Ask which can be transferred and verify the most important reader flows after migration. A successful list import does not prove that forms or unsubscribe requests still work.

## Related terms

[DMARC](https://digitalpublishingnews.com/dictionary/dmarc/)

[One-click unsubscribe](https://digitalpublishingnews.com/dictionary/one-click-unsubscribe/)

## Continue reading

[Gmail bulk-sender requirements: check authentication and unsubscribe in a delivered email](https://digitalpublishingnews.com/articles/gmail-bulk-sender-checks/): It checks sender authentication and suppression behavior on a delivered newsletter after a provider change.

## Sources

https://support.google.com/mail/answer/81126?hl=en

Editorial method: https://digitalpublishingnews.com/how-we-use-ai/

Canonical: https://digitalpublishingnews.com/dictionary/esp/